The 26-year-old Lake was competing for the fourth outfielder's job this spring, but that role went to Ezequiel Carrera. Lake will be part of an outfield mix with the Bisons that includes Darrell Ceciliani, Dalton Pompey and Domonic Brown.
Montero was developed as a catcher, but he hasn't played the position since 2013. He spent each of the past two years at designated hitter and first base, appearing in just 44 big league games over that span.
The 26-year-old was once one of the top prospects in the game, but has yet to live up to expectations. Despite his continued struggles, Montero hit .355 with 18 homers and 85 RBIs in 98 games at Triple-A Tacoma last season in the Mariners' organization.
Gregor Chisholm is a reporter for MLB.com. Follow him on Twitter @gregorMLB and Facebook, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.